Measurement and display of load of excavating blasted ground

ABSTRACT

This invention relates to a measuring and display system for loads applied upon digging blasted earth, which can contribute to accurate blasting. An operating direction of a bucket of an excavator is detected by pressure switches 15,16, while a pressure P B  in a bottom compartment 6S B  of a bucket cylinder is detected by a pressure sensor 17. A processor 23 computes a digging position based on signals from a boom angle sensor 18, an arm angle sensor 19, GPS 20 and a magnetic direction sensor 21, integrates pressures P B  during an ON period of the pressure switch 15, and transmits the thus-integrated pressure together with the digging position to a computer 30. The computer 30 displays a map of a lot under blasting and blasting positions on a display, and on the map, also displays the thus-transmitted digging position by a mark X and the integrated pressure by a numeral. With reference to this integrated pressure, a determination is made as to whether the blasting was proper or improper. The results of this determination are used for the next blasting.

TECHNICAL FIELD

This invention relates to a measuring and display system for loadsapplied upon digging blasted earth, which measures and displays loadsapplied upon digging earth by an excavator subsequent to blasting in alarge-scale mine or the like.

BACKGROUND ART

According to a mining method adopted in a large-scale open-pit (surface)mine or the like, earth is broken up beforehand by blasting, followed bythe digging of this broken-up earth with an excavator, for example, ahydraulic shovel. This will be described with reference to FIGS. 19, 20and 21. FIG. 19 is a plan view of the entirety of a large-scale mine. Inthis drawing, letter A indicates the whole area of the large-scale mine,which is as wide as several kilometers or longer in both length andwidth. Designated at signs A₁ -A_(n) are lots formed by dividing thewhole area A into smaller sections. Each lot is set so that it is about50 to 200 m in both length and width. Letter B indicates a minemanagement office which performs management of this mine site. The minemanagement office B is built at a position which is convenient for themanagement of both the inside and outside of the whole area A.

FIG. 20 is a plan view of one of the lots shown in FIG. 19. In thiscase, the lot A₁ depicted in FIG. 19 is shown in the form of a square.Signs P_(B1),P_(B2), . . . , P_(Bi), . . . indicate blasting positionsin the area A₁. Further, signs d₁,d₂ indicate distances between therespective explosives. In general, these distances are often setsubstantially equal. The placement positions (distances) and amounts ofexplosives are determined in view of cylindrical samples, which areobtained by conducting a geological survey at predetermined positions inthe whole area A, and a topographical map of the whole area.

FIG. 21 is a side view of a hydraulic shovel. After completion ofblasting by explosives placed in a lot, one or more hydraulic shovelsenter the lot to dig the blasted earth and then to load it on dumptrucks or the like. The blasted earth is transported to a predeterminedplace and is processed there. The hydraulic shovel illustrated in FIG.21 performs this digging work. In the drawing, there are shown a travelbase 1, a pivot cab 2, a cab 3, a boom 4 pivotally supported on thepivot cab 2, a boom cylinder 4S for driving the boom 4, an arm 5pivotally supported on the boom 4, an arm cylinder 5S for driving thearm 5, a bucket 6 turnably supported on the arm 5, a bucket cylinder 6Sfor driving the bucket 6, and a hinge 6p as a center line of turningmotion of the bucket. Letters C and D indicate a crowding direction anda dumping direction, respectively, in the operation of the bucket.Digging is performed when the bucket 6 is operated in the crowdingdirection C, whereas release of dug earth from the bucket is performedwhen the bucket 6 is operated in the dumping direction D.

Upon completion of the above-described digging work in one of the lots,explosives are next planted in the next lot. These explosives are fired,and the blasted earth is dug by the hydraulic shovels. The dug earth istransported away by dump trucks or the like. Digging work of theindividual lots is successively performed in the manner as describedabove.

The removal of overburden is considered to account for 80% of theabove-described work in the large-scale mine. Accordingly, whetherblasting is proper or improper has an overwhelming influence on theentire work. Described specifically, use of explosive in unduly smallamounts or setting of blasting positions at excessively large distancesmakes it impossible to break up earth sufficiently loosely. In thiscase, large digging loads are applied to the hydraulic shovels. Moretime is therefore spent digging, resulting in the digging not being ableto be performed as scheduled. This also leads to an inconvenience inthat dump trucks are kept on standby for a long time. On the other hand,use of explosive in excessively large amounts or setting of blastingpositions at excessively small distances results in excessively loosebreakage of earth. This leads not only to a problem of the diggingability of the hydraulic shovels not being able to be used fully butalso to another problem of cost for the explosive being substantial. Ablasting planner makes a blasting plan for the next lot by observing thestate of earth after the blasting or by learning of the state of diggingfrom the operators of the hydraulic shovels. Both this observation andlearning rely upon the sensations of the planner and those of theoperators, respectively, thereby making it impossible to perform optimalblasting in many instances.

An object of the present invention is to provide a measuring and displaysystem for loads applied upon digging blasted earth, which can solve theabove-described inconveniences and problems of the conventional art andcan contribute to accurate blasting.

DISCLOSURE OF THE INVENTION

To achieve the above-described object, the invention of claim 1 featuresthe construction of a measuring system for loads, which are applied upondigging blasted earth, by crowding operation detecting means fordetecting a crowding operation of a bucket of an excavator which is in adigging operation of earth after blasting and pressure detection meansfor detecting, as a digging load, a bottom pressure of a bucket cylinderof the excavator upon detection of the crowding operation by thecrowding operation detecting means.

The invention of claim 2 features the inclusion of digging timedetection means for detecting digging time of the excavator in themeasuring system of claim 1.

The invention of claim 3 features the construction of a measuring systemfor loads, which are applied upon digging blasted earth, by crowdingoperation detecting means for detecting a crowding operation of a bucketof an excavator which is in a digging operation of earth after blasting;loading step determination means for determining a loading stepperformed by the excavator, pressure detection means for detecting, as adigging load, a bottom pressure of a bucket cylinder of the excavatorupon detection of the crowding operation by the crowding operationdetecting means, and classification means for classifying the diggingload, which has been detected by the pressure detection means, as thedigging load in the loading step as determined by the loading stepdetermination means or as a digging load in a step other than theloading step.

The invention of claim 4 features the construction of a measuring systemfor loads, which are applied upon digging blasted earth, by crowdingoperation detecting means for detecting a crowding operation of a bucketof an excavator which is in a digging operation of earth after blasting,and preset pressure detection means for detecting, as a digging load, abottom pressure of a bucket cylinder of the excavator when the bottompressure arises at least to a preset pressure while the crowdingoperation is being detected by the crowding operation detecting means.

The invention of claim 5 features the inclusion of load quantitydetection means, which is for determining the time or number ofdetections in each of which a pressure at least equal to the presetpressure is detected by the preset pressure detection means, in themeasuring system of claim 4.

The invention of claim 6 features that, in the measuring systemaccording to claim 1 or 2, a display system for loads applied upondigging blasted earth is constructed by arranging digging positiondetecting means for detecting a digging position by the excavator anddisplay means for displaying the digging load detected by the pressuredetection means or a value or color corresponding to the digging loadand the digging position detected by the digging position detectingmeans.

The invention of claim 7 features that, in the measuring systemaccording to claim 3, a display system for loads applied upon diggingblasted earth is constructed by arranging digging position detectingmeans for detecting a digging position by the excavator and displaymeans for displaying the digging load, which has been detected by thepressure detection means or a value or color corresponding to thedigging load, while specifying whether the digging load or the value orcolor is one in the loading step or one in the step other than theloading step as determined by the loading step determination means, andthe digging position detected by the digging position detecting means.

The invention of claim 8 features that, in the measuring systemaccording to claim 5, a display system for loads applied upon diggingblasted earth is constructed by arranging digging position detectingmeans for detecting a digging position by the excavator and displaymeans for displaying the time or number, which has been detected by theload quantity detection means, or a color corresponding to the time ornumber, and the digging position detected by the digging positiondetecting means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a measuring and display system according toa first embodiment of the present invention for loads applied upondigging blasted earth. FIG. 2 is a diagram illustrating a direction of amagnetic direction sensor. FIG. 3 is a system configuration diagram of aprocessor depicted in FIG. 1. FIG. 4 is a system configuration diagramof a computer shown in FIG. 1. FIG. 5 is a flow chart illustrating anoperation of the system shown in FIG. 1. FIG. 6 is another flow chartillustrating another operation of the system shown in FIG. 1. FIG. 7 isa further flow chart illustrating a further operation of the systemshown in FIG. 1. FIG. 8 is a still further flow chart illustrating astill further operation of the system shown in FIG. 1. FIG. 9 is a stillfurther flow chart illustrating a still further operation of the systemshown in FIG. 1. FIG. 10 is a still further flow chart illustrating astill further operation of the system shown in FIG. 1. FIG. 11 is apartly enlarged front view of a screen of a display. FIG. 12 is a frontview of the screen, illustrating another example of display on thedisplay. FIG. 13 is a block diagram of a measuring and display systemaccording to a second embodiment of this invention for loads appliedupon digging blasted earth. FIG. 14 is a flow chart illustrating anoperation of the system shown in FIG. 13. FIG. 15 is a flow chartillustrating an operation of the system shown in FIG. 13. FIG. 16 is apartly-enlarged front view of a screen of the display system. FIG. 17 isa cross-sectional view of a blasted bottom of a pit. FIGS. 18A & 18B area timing chart illustrating an operation of a third embodiment. FIG. 19is a plan view of the entirety of the large-scale mine. FIG. 20 is aplan view of the single lot shown in FIG. 20. FIG. 21 is a side view ofa hydraulic shovel.

BEST MODES FOR CARRYING OUT THE INVENTION

The present invention will hereinafter be described based on theembodiments illustrated in the drawings.

FIG. 1 is the block diagram of the measuring and display systemaccording to the first embodiment of the present invention for loadsapplied upon digging blasted earth. In the diagram, there are shown thebucket cylinder 21 depicted in FIG. 21, a rod compartment 6S_(R) of thebucket cylinder 6S, and a bottom compartment 6S_(B). Also illustratedare a hydraulic pump 10 for the hydraulic shovel, a reservoir 11, acontrol valve 12 interposed between the hydraulic pump 10 and the bucketcylinder 6S, and an operating lever 13 for the bucket 6. Numeral 14indicates a pilot valve, which according to an operation of theoperating lever 13, supplies a pilot pressure to the control valve 12 todrive the control valve 12. Designated at numeral 15 is a pressureswitch, which is adapted to detect an operation of the bucket 6 in acrowding direction by the operating lever 13 and which outputs a signalL_(C) when the operating lever 13 is operated in the crowding direction.Designated at numeral 16 is another pressure switch, which is adapted todetect an operation of the bucket 6 in a dumping direction by theoperating lever 13 and which outputs a signal L_(D) when the operatinglever 13 is operated in the dumping direction. Numeral 17 indicates afurther pressure sensor for detecting a pressure P_(B) in the bottomcompartment 6S_(B) of the bucket cylinder 6S. Also depicted are an anglesensor for detecting a boom angle α of the hydraulic shovel and anotherangle sensor for detecting an arm angle β of the hydraulic shovel.

Numeral 20 indicates GPS (Global Positioning System) mounted on thehydraulic shovel, which receives signals at an antenna 20A from asatellite and outputs an absolute coordinate P_(G) of the hydraulicshovel on the earth. Designated at numeral 21 is a magnetic directionsensor arranged on a center line of revolving motion of the pivot cab 2of the hydraulic shovel. Referring to FIG. 2, a description will be madeof a direction detected by the magnetic direction sensor. In FIG. 2,there are shown the center line 2C of revolving motion of the pivot cab2 and axes 4,5 of the boom 4 and arm 5, said axes being indicated bysolid lines. Sign 6p indicates a hinge as a center line of turningmotion of the bucket. The magnetic direction sensor 21 is adapted todetect how many degrees the forward direction of the pivot cab 2, thatis, the direction of each of the boom 4, arm 5 and bucket 6 is inclinedfrom northward of the geomagnetism, and the angle so detected isindicated by letter θ in FIG. 2 and is outputted as direction data.Designated at numeral 22 is a start/stop switch, which the hydraulicshovel is equipped with and, when operated, outputs a signal S_(S). Thesignal S_(S) can be either a signal indicating turning-on of the startswitch or a signal indicating turning-on of the stop switch. Numeral 23indicates a processor mounted on the hydraulic shovel and composed of acomputer (the construction of this processor will be describedsubsequently herein), and numeral 24 indicates a radiotransmitter/receiver equipped with an antenna 24A.

Designated at numeral 30 is a computer installed in the mine managementoffice B shown in FIG. 19. Numeral 31 indicates a radiotransmitter/receiver, which is equipped with an antenna 31A and receivesvarious data, which has been outputted from the processor 23, via theradio transmitter/receiver 24. Designated at numeral 32 is a display forperforming a desired display on the basis of data from the computer 30.

FIG. 3 is the system configuration diagram of the processor 23 depictedin FIG. 1. In the diagram, numeral 23 indicates the processor. Numeral231 indicates an input interface 231, through which individual signalsshown in FIG. 1 are inputted, and is equipped with an A/D converter.Also illustrated are a central processing unit (CPU) 232 for performingvarious computation and control, a read-only memory (ROM) 233 forstoring therein processing programs and the like for CPU 232, a randomaccess memory (RAM) for storing therein the results and the like ofcomputation and control, a timer 235 for outputting time signals, and anoutput interface 236 through which data, which has been obtained at theprocessor 23, is outputted. Stored in ROM 233 are included a start/stopprogram 233a, a load pressure sampling program 233b, a digging positionsampling program 233c, and an ending program 233d.

FIG. 4 is the system configuration diagram of the computer 30 shown inFIG. 1. In the diagram, numeral 30 indicates a computer. Alsoillustrated are an input interface 301 through which signals areinputted from the radio transmitter/receiver shown in FIG. 1, a centralprocessing unit (CPU) 302 for performing various computation andcontrol, a read-only memory (ROM) 303 for storing therein processingprograms and the like for CPU 302, a random access memory (RAM) 304 forstoring therein the results of computation and control, and an outputinterface 305 through which data obtained at the computer 30 isoutputted. Stored in ROM 303 include blasting data 303a, load pressuredata 303b, and a display program 303c. The blasting data 303a consistsof a map of a digging work site, planted positions of explosives, andamounts of the explosives.

Operation of this embodiment will next be described with reference tothe flow charts of FIG. 5 through FIG. 10. Upon digging earth subsequentto the completion of blasting, a hydraulic shovel operator turns on thestart switch of the start/stop switch 22 so that a signal S_(S) isoutputted. CPU 232 of the processor 23 monitors an input of the signalS_(S) in accordance with the start program 233a shown in FIG. 5 (StepS₁₀) and, when the signal S_(S) is inputted, sets a digging counter n, alever-operated time counter C_(TL) of the operating lever 13 and anintegrated value P_(D) of pressures P_(B) detected by the pressuresensor 17 at 0, respectively, and turns off a crowd flag F_(C) and adump flag F_(D) (step S₁₁), whereby the start program is ended.

Based on an output from the timer 235, CPU 232 next activates the loadpressure sampling program 233b, which is shown in FIG. 6 and FIG. 7, forexample, at intervals of 10 msec. When the operating lever 13 isoperated in the direction to crowd the bucket 6 (in other words, whendigging is performed), this load pressure sampling program, in order toconfirm that an operation signal L_(C) is not a noise but is areflection of the operator's intention, determines whether or not thesignal has been inputted continuously for a predetermined time, forexample, for 0.3 sec. When the signal is confirmed to have lasted forthe predetermined time, it is determined that digging has beenperformed. Similar confirmation is also performed with respect to anoperation signal L_(D) which is outputted when earth is dumpedsubsequent to the completion of the digging. Further, when theseconfirmations have been made, an operation is performed for the firsttime to set predetermined values, respectively, and to input them.

When the load pressure sampling program 233b is activated subsequent tothe performance of the start program shown in FIG. 5, CPU 232 determineswhether or not the operation signal L_(C), which indicates the operationof the operating lever 13 in the crowding direction, has been inputted(step S₂₀ shown in FIG. 6). When the signal is not determined to havebeen inputted, a crowding-operation-determining counter value C_(C) isset at 0 and the crowd flag is turned off (step S₂₁), followed by thedetermination as to whether or not the operating signal L_(D) indicatingoperation of the operating lever 13 in the dumping direction has beeninputted (step S₂₂). When the signal is not determined to have beeninputted, a damping-operation-determining counter value C_(D) is set at0 and the dump flag is turned off (step S₂₁). The processing is thencontinued to step S₂₄ shown in FIG. 7, where a determination is made asto whether or not the crowd flag F_(C) is ON. If it is not ON, it islikewise determined whether or not the dump flag is ON (step S₂₅). If itis not ON, the processing is ended.

When the operator operates the operating lever 13 in the crowdingdirection to perform digging while such processing is performed atintervals of 10 msec, this operation is determined by the processing instep S₂₀, and CPU 232 then determines whether or not the crowd flag isON (step S₂₆). As the crowd flag has not been turned on in this case, itis determined whether or not the crowding-operation-determining countervalue C_(C) has reached a predetermined value C_(CO) (step S₂₇).Assuming that the value C_(CO) is 30 times, for example, it takes 0.3sec until the crowding-operation-determining counter value C_(C)increases from 0 to 30 because the load pressure sampling program 233bis executed at intervals of 10 msec in the above-described example.Within this time, the operator's intention of the operation isconfirmed.

Described specifically, when the crowding-operation-determining countervalue C_(C) has not reached the predetermined value C_(CO), "1" is addedto the crowding-operation-determining counter value C_(C) (step S₂₈) andthe routine proceeds through steps S₂₂, S₂₃, S₂₄ and S₂₅, whereby theprocessing is ended. When this processing is repeated at intervals of 10msec, the crowding-operation-determining counter value C_(C) eventuallyreaches the value C_(CO). By determining this as a result of theprocessing in step S₂₇, CPU 232 confirms that the operator has operatedthe operating lever 13 in the crowding direction. CPU 232 turns on thecrowd flag, adds "1" to the digging counter n, stores a current diggingposition P_(6P) (the current position of the hinge 6p) and also acurrent time, and turns off the dump flag (step S₂₉). The routine thenproceeds through steps S₂₂, S₂₃, S₂₄ and S₂₅, whereby the processing isended.

Here, the above-described digging position P_(6P) is obtained byperforming the digging position sampling program 233c shown in FIG. 8.Namely, CPU 232 reads a signal P_(G) from GPS 20, a signal θ from themagnetic direction sensor 21, and signals α,β from the boom angle sensor18 and arm angle sensor 19 (step S₄₀ shown in FIG. 8); computes ahorizontal distance L between the point of connection of the boom 4 onthe pivot cab 2 by using a horizontal distance (already known) betweenthe center line 2C of revolving motion of the hydraulic shovel and thepoint of connection of the boom 4 on the pivot cab 2, and the anglesα,β; and then computes the digging position (the position of the hinge6p of the bucket) P_(6P) on the basis of the previously-read signalP_(G), the computed distance L and the direction θ (step S₄₁).

Upon an elapsed time of 10 msec since the completion of the processingin step S₂₉, the load pressure sampling program is executed again. Sincethe crowd flag F_(C) has already been turned on in step S₂₉ of thepreceding processing, this ON state of the crowd flag is determined instep S₂₆ and the processing advances to step S₂₄ via steps S₂₂,S₂₃. Asthe crowd flag F_(C) is ON, this ON state is determined in step S₂₄ andthe processing advances to step S₃₀. In step S₃₀, CPU 232 adds "1" tothe count value C_(TL) of crowding operation time and also adds acurrent detection value (load pressure) of the pressure sensor 17 to anintegrated value of load pressures until that time (in this case, "0"because the digging is the first digging). The routine then advancesthrough step S₂₅ so that the processing is ended. This processing isexecuted at intervals of 10 msec during the digging operation, and ineach execution, "1" is added to the count value C_(TL) of crowdingoperation time and the load pressure is integrated.

Upon completion of the digging operation, the operator operates theoperating lever 13 in the dumping direction. This operation isdetermined by the processing in step s₂₂ subsequent to the processingsin steps S₂₀,S₂₁. CPU 232 then determines whether or not the dump flagF_(D) is ON (step S₃₁). Because the operating direction of the buckethas been just changed over to the dumping direction, the dump flag F_(D)is in the OFF state. It is therefore determined whether or not thedumping-operation-determining count value C_(D) has reached theabove-mentioned value C_(CO) (step S₃₂). As the value C_(CO) has notbeen reached, "1" is added to the dumping-operation-determining countvalue C_(D) (step S₃₃). The routine then advances through steps S₂₄,S₂₅,whereby the processing is ended. Similarly to the case of the operationin the crowding direction, this processing is repeated until C_(D)becomes equal to C_(CO) (C_(D) =C_(CO) ; until an operation in thedumping direction is confirmed). Upon confirmation of C_(D) =C_(CO) instep S₃₂, CPU 232 then turns on the dump flag F_(D) and turns off thecrowd flag F_(C) (step S₃₃). Subsequent to the processing in step S₂₄,the ON state of the dump flag F_(D) is determined in step S₂₆, and it isdetermined whether or not the digging number n has been updated (stepS₃₄). Since the digging number n has been updated as a result of theaddition of "1" in step S₂₉ in this case, CPU 232 performs theprocessing of step S₃₅.

By the processing in step S₃₅, the following computations are performed:

[1] a count value C_(TL) (n-1) of crowding operation time up to thepreceding digging is subtracted from the current integrated value C_(TL)(n) of count values C_(TL) of crowing operation time to obtain a currentcount value ΔC_(TL) (n) of crowding operation time;

[2] the current count value ΔC_(TL) (n) of crowding operation time ismultiplied by the interval (10 msec) of repeated executions of the loadpressure sampling program 233c to obtain a current digging time ΔT_(L) ;

[3] the integrated value P_(D) (n-1) of load pressures up to thepreceding digging is subtracted from the current integrated value P_(D)(n) of load pressures to obtain a current load pressure ΔP_(D) (n); and

[4] the current load pressure ΔP_(D) (n) is divided by a current countvalue ΔC_(TL) (n) of crowding operation time to obtain a current averageload pressure P_(A).

The results of the computations are outputted as data to the radiotransmitter/receiver 24. The radio transmitter/receiver 24 wirelesslytransmits the thus-inputted data to the computer 30 at the minemanagement office B.

At the hydraulic shovel, the above-described processing is repeated bythe processor 23 whenever the bucket 6 is operated in the crowdingdirection. Upon completion of each bucket operation in the crowdingdirection, the above-mentioned data are hence transmitted to thecomputer 30 at the mine management office B. Upon completion of diggingwork in one of the lots, the operator turns on the stop switch of thestart/stop switch 22 so that the ending program 233d shown in FIG. 9 isexecuted. In other words, CPU 232 watches whether or not the stop switch22 has been turned on (step S₅₀). When the stop switch is determined tohave been turned on, CPU 23 outputs a work-ended status and also outputsa current time T_(o), an integrated value T_(L) of crowding operationtime and an integrated value P_(D) of load pressures, both to the radiotransmitter/receiver 24 (step S₅₁), whereby the processing is ended.

The foregoing is the processing on the side of the excavator, and on theside of the mine management office B, the following processing isperformed for data which are transmitted from the side of the excavatorupon each digging operation.

Before initiation of digging of each digging lot by the hydraulicshovel, the computer 30 displays the map of the digging lot andexplosive-planted positions on the screen of the display 32 on the basisof the blasting data 303a. In this state, the display program 303c shownin FIG. 10 is repeatedly executed, and CPU 302 determines whether or notnew data have been transmitted from the side of the excavator (stepS₆₀). Upon determination of receipt and input of data at the radiotransmitter/receiver 31 from the side of the excavator, CPU 303c writesinputted digging position data P_(6P) and a load pressure ΔP_(D) (n) ofthe current digging in the load pressure data area 303b, displays a markX on the screen at a position corresponding to the digging position dataP_(6P), and also displays the load pressure ΔP_(D) (n) of the currentdigging in the vicinity of the mark X (step S₆₁). It is then determinedwhether or not the stop switch has been turned on (step S₆₂). If thestop switch has not been turned on, the routine returns to theprocessing in step S₆₀. Whenever new data are inputted, a mark X and aload pressure are stored and displayed.

FIG. 11 is the enlarged fragmentary front view of the screen of thedisplay. In this diagram, sign 32D indicates the screen of the display32. P_(Bi) indicates one of the explosive-planted positions, and diggingpositions and load pressures around the explosive-planted positionP_(Bi) are indicated by marks X and numerals, respectively. In thiscase, each load pressure is not an actual load pressure but is indicatedas a corresponding level out of 0 to 100 levels into which actual loadpressures are divided. Display of other positions is effected likewise.

When the digging work is completed and the stop switch is turned on bythe operator, CPU 302 determines it in step S₆₂, and displays anintegrated value T_(L) of crowding operation time and an integratedvalue P_(D) of load pressures, both transmitted following step S₅₁ shownin FIG. 9, and also subtracts from the current time t_(o) a time t_(o)(1) at the time of the initiation of the digging work and displays atotal working time required for the digging.

FIG. 12 is the front view of the screen of the display, illustratinganother example of display. In this diagram, sign 32D indicates the samescreen as that depicted in FIG. 11. Further, sign P_(B1) indicates ablasting position. In this example of display, a lot is subdivided intosmaller lots (for example, 5 m squares), and with respect to each ofthese subdivided lots, a digging time and an average value of loadpressures (levels) are displayed. In this case, the display program 303cshould of course be added with a step for computing the digging time andthe average value of load pressure levels.

In the example of display shown in FIG. 11 and FIG. 12, the loadpressures are displayed by numerical values by way of example. It ishowever possible to display each load pressure or load pressure level ina corresponding color by dividing load pressures or load pressure levelsinto plural ranges in accordance with their values and assigningdifferent colors to the individual ranges, for example, in such a waythat a high load pressure range is indicated by red, a low load pressurerange is indicated by blue and an intermediate load pressure range isindicated by green.

As has been described above, according to this embodiment,bucket-digging positions and load pressures in the crowding direction atthese positions are collected on the side of the excavator in thedigging of earth after blasting, these digging positions and loadpressures are transmitted to the mine office, and at the mine office,the digging positions and the load pressures or load pressure levels aredisplayed on the map of the blasted lot and the blasted positions on thebasis of the transmitted data. With reference to these information, theblasting planner can therefore perform blasting of the next lot moreproperly. Described specifically, with reference to theexplosive-planted positions, the digging positions and the loadpressures or load pressure levels on the map, the blasting plannerdetermines inter alia whether or not the amount of the blastingexplosive was too little at each position where the load pressure wastoo high, whether or not another geological survey is needed when theamount of the explosive is not considered to be little, or whether ornot the amount of the explosive should be reduced when the load pressureis low. This makes it possible to perform the blasting of the next lotproperly. Further, the number of dump trucks to be used is taken intoconsideration. When many trucks are available for use, the waiting timeof each dump truck can be minimized by lowering load pressures andmaking the digging time shorter. From this viewpoint, it is alsopossible to make a determination in view of load pressures obtained by ameasurement according to this embodiment as to whether or not the amountof explosive should be increased (load pressures should be lowered).When the number of dump trucks available for use is small in contrast,the overall transportation work cannot be inconvenienced even when thedigging time becomes somewhat long. From this viewpoint, the amount ofexplosive can be determined in view of the load pressures so obtained.Concerning the excavators, load pressures are displayed from time totime so that, if there are many positions of high load pressures, one ormore excavators may added to smoothly perform the work.

If a digging time is referred to, unskillfulness of the operator or theoccurrence of a mechanical trouble may be gathered when the digging timeis long in spite of low load pressures. Further, a display of loadpressures in colors makes it possible to determine with a single glancewhether the overall blasting was proper or improper. In addition, it isalso possible to determine, from the display of an integrated valueT_(L) of crowding operation time and a total working time required fordigging up to an integrated value P_(D) of load pressures, whether ornot the overall blasting is proper or improper.

A description will next be made about the second embodiment of thepresent invention.

FIG. 13 is the block diagram of the measuring and display systemaccording to the second embodiment of the present invention for loadsapplied upon digging blasted earth. In this diagram, elements ofstructure identical or equivalent to the corresponding elements shown inFIG. 1 are identified by like reference signs, and their description isomitted. Operations of the bucket in the crowding direction were allreferred to as "digging" in the above-described first embodiment,whereas "digging" operations will be classified further depending on theactual work in this embodiment. Namely, it is the common practice indigging work to employ such work procedures that, when the number oftrucks is small, blasted earth is dug to heap the earth at one place andthe thus-heaped earth is loaded on each dump truck upon its arrival. Inthis embodiment, "digging" operations are classified into digging ofblasted earth (digging directly associated with an actual load) anddigging upon loading the earth on each dump truck. This classificationis conducted by a work step input switch 25. The work step input switch25 is composed of a DIG switch and a LOAD switch. The DIG switch isturned upon digging blasted earth, whereas the LOAD switch is turned onupon digging the earth for loading it on each dump truck. Theconstruction other than the work step input switch 25 is the same as theconstruction illustrated in FIG. 1 although there are some differencesin the processing steps by the processor 23 and the computer 30.

Operations of this embodiment will next be described with reference tothe flow chart shown in FIG. 14 and FIG. 15. An operator of a hydraulicshovel turns on the DIG switch upon digging blasted earth or the LOADswitch upon digging the earth for loading it on a dump truck. In thisstate., a load pressure sampling program is executed as in the precedingembodiment. Namely, an operation of the operating lever 13 in thecrowding direction is confirmed, and a count value C_(TL) of crowdingoperation time and a bucket load pressure P_(B) are added. When theoperating lever 13 is next operated in the dumping direction, thisoperation is confirmed. In the preceding embodiment, operations up tothis point were performed in step S₂₀ to step S₃₄, and processing forthe computation and output of the individual data was then immediatelyperformed in step S₃₅. In this embodiment, operations up to step S₃₄ arethe same as those in the preceding embodiment but the subsequentoperations differ.

Described specifically, when it is determined in step S₃₄ that thedigging number n has been updated, a determination is next made as towhether the DIG switch or the LOAD switch is ON in the work step switch25 (step S₃₆ shown in FIG. 14) A flag F₂₅ for the work step input switch25 is set at "1" when the DIG switch is ON, (step S₃₇) but the flag F₂₅for the work step input switch 25 is set at "0" when the LOAD switch isON (step S₃₈), and the routine then advances to step S₃₅₀. In step S₃₅₀,the same computation as that in step S₃₅ in FIG. 7 is performed toobtain the same individual data, and the data of the flag F₂₅ iscollected and is outputted together with the individual data to theradio transmitter/receiver 24.

At the computer 30, on the other hand, a display program is executed asin the preceding embodiment. When new data is determined to have beeninputted (step the thus-inputted digging position data P_(6P) andcurrent digging load pressure ΔP_(D) (n) are written together with thedata of the flag F₂₅ in the load pressure data area 303b, and further, amark X is displayed at a position on the screen, said positioncorresponding to the digging position data P_(6P) and the currentdigging load pressure ΔP_(D) (n) is displayed in the vicinity of themark (step S₆₁₀). This display of the mark X and the load pressure datais performed in the same manner as in the preceding embodiment, but inthis embodiment, the mark X and the load pressure data are displayed indifferent colors in accordance with the data of the flag F₂₅.Processings in steps S₆₂ and S₆₃, which follows the aforementionedprocessing, are the same as the corresponding processings in thepreceding embodiment.

FIG. 16 is the enlarged fragmentary front view of the screen of thedisplay. In this diagram, sign 32D indicates the screen of the display32. P_(Bi) indicates one of the explosive-planted positions, and diggingpositions and load pressures around the explosive-planted positionP_(Bi) are indicated by marks X and numerals, respectively. In thiscase, each load pressure is not an actual load pressure but is indicatedas a corresponding level out of 0 to 100 levels into which actual loadpressures are divided. Display of other positions is effected likewise.In this embodiment, digging positions and load pressure levels aredisplayed in different colors depending on the digging of blasted earthor the digging for loading. Around the position P_(Bi), diggingpositions and load pressure levels when the data of the flag F₂₅ is "1"(upon digging blasted earth) and digging positions and load pressurelevels when the data of the flag F₂₅ is "0" (upon digging for loading)are therefore observed in two groups divided in different colors. In thediagram, sign 32D_(D) indicates the group upon digging the blasted earthand sign 32D_(L) designates the group upon digging for loading.

Incidentally, this display is not limited to that shown in FIG. 16, butcan be in the form of the display shown in FIG. 12. In such a case,small lots are displayed with a time and a load pressure in differentcolors in each lot.

In addition to the advantageous effects of the preceding embodiment,this embodiment can bring about an additional advantageous effect inthat the proper/improper determination of blasting can be conducted moreeasily and accurately because load pressures are displayed byclassifying them into load pressures upon digging blasted earth andthose upon digging for loading.

A description will next be made about the third embodiment of thepresent invention. The overall construction of this embodiment issubstantially the same as the construction illustrated in FIG. 1 exceptthat the pressure switch 16 is omitted and the processor 23 and thecomputer 30 perform different processing steps. FIG. 17 and FIGS. 18A &18B diagrammatically illustrate a measurement according to thisembodiment to determine a load applied upon digging blasted earth. FIG.17 is the cross-sectional view of a blasted bottom of a pit, and FIGS.18A & 18B is the timing chart showing an operation of this embodiment.

In FIG. 17, sign G₁ indicates a digging-finished bottom in the blastedbottom of the pit and sign G₂ indicates an unexcavated earth on theblasted bottom of the pit. In the unexcavated earth G₂, sign G₂₁indicates a portion broken loose by blasting and sign G₂₂ indicates aportion not broken fully loose in spite of the blasting. Aftercompletion of the digging at the digging-finished bottom G₁, a hydraulicshovel performs digging of the adjacent unexcavated earth G₂ while usingthe digging-finished bottom G₁ as a foundation. Incidentally, blastingis conducted by making holes in a bottom of a pit and then settingexplosives there. The earth is therefore broken to a substantial depth.Nonetheless, the breakage of the earth in a deep section becomesinsufficient compared with that of the earth in a section close to thesurface. Whether the blasting was proper or improper is determineddepending on how many sections of insufficient earth breakage exist.This embodiment is therefore to prepare data, which is to be transmittedto the mine management office B, by collecting only digging loads insections of insufficient earth breakage.

An operation of this embodiment will hereinafter be described withreference to the timing chart shown in FIGS. 18A & 18B. FIG. 18(a) isthe diagram illustrating an operation of the operating lever, in whichtime is plotted along the abscissa and the stroke of the operating leveris plotted along the ordinate. On the other hand, FIG. 18(b) is adiagram illustrating pressures in the bottom compartment 6S_(B) of thebucket cylinder 6S, in which time is plotted along the abscissa andpressure is plotted along the ordinate. The start switch of thestart/stop switch 22 is turned on upon initiation of digging, and adigging position under digging is calculated by the same method as inthe first embodiment. When it is determined from a signal L_(C) that theoperating lever 13 has been operated in the crowding direction (thisdetermination method is the same as the determination method in thefirst embodiment), the processor 23 receives detection pressures P_(B)of the pressure sensor 17 and compares them with a preset pressureP_(S). When the detection pressures P_(B) are equal to or higher thanthe preset pressure P_(S), their times or durations are measured (thesetimes are indicated by t₁,t₂,t₃ in the diagram) and the number of thepressures (3 times in the case illustrated in the drawing) is counted.Incidentally, sign P_(R) indicates a relief pressure in the diagram.These times are summed, and are outputted together with the number ofthe pressures to the radio transmitter/receiver 24 and are thentransmitted to the computer 30.

The computer 30 stores the thus-transmitted data in the load pressuredata area 303b, and in accordance with a display program, displays thedigging position by a mark X on the screen of the display 32 and alsodisplays the above-described total time or number or both of them in thevicinity of the mark X. When the stop switch is turned on, a totaloperation time, a total elapsed time, an integrated value of theabove-described total times, or an integrated value of theabove-described numbers is displayed on the screen.

This embodiment can bring about the same advantageous effects as thepreceding embodiments.

In the above description of each of the embodiments, the loader-typehydraulic shovel shown in FIG. 21 was described as an excavator by wayof example. Needless to say, a back-hoe-type hydraulic shovel can alsobe used. Further, whether blasting or the like is proper or improper canbe estimated to a certain extent by depending upon only data of diggingloads without using a display. The start/stop switch may be arranged onthe side of the mine management office instead of installing it on theside of the excavator, and the data of the start/stop switch may betransmitted from the side of the mine management office to the side ofthe excavator by the radio transmitter/receiver. In addition, it is alsopossible to use a pressure sensor in place of the pressure switch forthe detection of an operation of the operating lever, to input adetection signal from the pressure sensor to the processor, and then todetermine that the operating lever has been operated when the pressurehas reached a predetermined value or higher. Setting of thepredetermined value at an appropriate value can obviate the processingfor the confirmation of an operation of the operating lever at theprocessor.

Concerning the digging positions, the example making use of GPS wasdescribed. It is also possible to use a laser projector and a reflectingmirror in place of GPS. The reflecting mirror mounted on the excavatoris tracked from the mine management office. The relative position of theexcavator from the mine management office can then be measured as adigging position. As a further example, a digging position was alsocalculated by using a boom angle and an arm angle. Since the positionsof the boom and arm in digging are not significantly different from thepositions of the boom and arm in loading, a predetermined distance fromthe pivot of the boom may be chosen in advance for use in thecalculation of each digging position without relying upon a boom angleand an arm angle.

Capability of Exploitation in Industry

As has been described above, the present invention detects a bottompressure of a bucket cylinder in a crowding operation period of a bucketof an excavator which is in a digging operation of earth after blasting,detects the digging position by the excavator, and then shows both ofthem on a display. This makes it possible to perform proper blasting.

What is claimed is:
 1. A measuring system for loads applied upon diggingblasted earth, comprising crowding operation detecting means fordetecting a crowding operation of a bucket of an excavator which is in adigging operation of earth after blasting; and pressure detection meansfor detecting, as a digging load, a bottom pressure of a bucket cylinderof said excavator upon detection of said crowding operation by saidcrowding operation detecting means.
 2. The measuring system according toclaim 1, further comprising digging time detection means for detectingdigging time of said excavator.
 3. The measuring system according toclaim 2, further comprising:digging position detecting means fordetecting a digging position by said excavator; and a display systemcomprising display means for displaying said digging load detected bysaid pressure detection means or a value or color corresponding to saiddigging load and said digging position detected by said digging positiondetecting means.
 4. The measuring system according to claim 3, whereinsaid display means stores blasting positions and displays said blastingpositions as desired.
 5. The measuring system according to claim 1,further comprising:digging position detecting means for detecting adigging position by said excavator; and a display system comprisingdisplay means for displaying said digging load detected by said pressuredetection means or a value or color corresponding to said digging loadand said digging position detected by said digging position detectingmeans.
 6. The measuring system according to claim 5, wherein saiddisplay means stores blasting positions and displays said blastingpositions as desired.
 7. A measuring system for loads applied upondigging blasted earth, comprising crowding operation detecting means fordetecting a crowding operation of a bucket of an excavator which is in adigging operation of earth after blasting; loading step determinationmeans for determining a loading step performed by said excavator;pressure detection means for detecting, as a digging load, a bottompressure of a bucket cylinder of said excavator upon detection of saidcrowding operation by said crowding operation detecting means; andclassification means for classifying said digging load, which has beendetected by said pressure detection means, as said digging load in saidloading step as determined by said loading step determination means oras a digging load in a step other than said loading step.
 8. Themeasuring system according to claim 7, further comprising:diggingposition detecting means for detecting a digging position by saidexcavator; and a display system comprising display means for displayingsaid digging load, which has been detected by said pressure detectionmeans or a value or color corresponding to said digging load, whilespecifying whether said digging load or said value or color is one insaid loading step or one in said step other than said loading step asdetermined by said loading step determination means, and said diggingposition detected by said digging position detecting means.
 9. Themeasuring system according to claim 8, wherein said display means storesblasting positions and displays said blasting positions as desired. 10.A measuring system for loads applied upon digging blasted earth,comprising crowding operation detecting means for detecting a crowdingoperation of a bucket of an excavator which is in a digging operation ofearth after blasting; and preset pressure detection means for detecting,as a digging load, a bottom pressure of a bucket cylinder of saidexcavator when said bottom pressure arises at least to a preset pressurewhile said crowding operation is being detected by said crowdingoperation detecting means.
 11. The measuring system according to claim10, further comprising load quantity detection means for determining thetime or number of detections in each of which a pressure at least equalto said preset pressure is detected by said preset pressure detectionmeans.
 12. The measuring system according to claim 11, furthercomprising:digging position detecting means for detecting a diggingposition by said excavator; and a display system comprising displaymeans for displaying the time or number, which has been detected by saidload quantity detection means, or a color corresponding to said time ornumber, and said digging position detected by said digging positiondetecting means.
 13. The measuring system according to claim 12, whereinsaid display means stores blasting positions and displays said blastingpositions as desired.